Lymphocytopenia (lymphopenia) is a decrease in the level of lymphocytes less than 1,800 (18% of the total number of leukocytes) in 1 μl of blood. In children, due to physiological lymphocytosis due to leukocytic decussation, lymphocytopenia is recognized as below 3,500-4,500. The cause is considered to be infectious and autoimmune diseases, malignant blood diseases. The clinical picture is determined by the underlying pathology. Lymphopenia can be manifested by hypoplasia of the tonsils of the pharyngeal ring, activation of opportunistic infections. The concentration of lymphocytes is measured in the complete blood count (CBC). To return them to normal levels, it is necessary to treat the disease that caused lymphocytopenia.
There are no threshold numerical values for separating lymphocytopenia according to severity; moderate and severe are conventionally distinguished. In relation to lymphocytes to other types of leukocytes, the following types of lymphocytopenia are distinguished:
Lymphocytopenia is not necessarily a sign of any disease. The cause may be various physiological conditions, such as prolonged stress. Under stress, adrenal hormones (glucocorticosteroids) are released into the blood, which have a destructive effect on lymphocytes. Lymphocytopenia can also be seen in protein deficiency, so it is not uncommon in starvation or in people on a vegetarian or vegan diet.
Under the influence of some lymphotropic viruses, accelerated death of lymphocytes occurs. The most common and dangerous infectious cause of lymphocytopenia is the human immunodeficiency virus (HIV). It binds to special receptors (CD4) on the surface of T-lymphocytes (T-helpers), penetrates into the cell, where it actively multiplies and leads to its death. The decrease in the number of T-helpers occurs both due to the direct damaging effect of the virus, and due to the activation of apoptosis (programmed cell death) and autoimmune damage.
At the very beginning of infection, the level of lymphocytes may, on the contrary, increase with the development of leukocytosis as an immune response to a foreign microorganism, but then a rapid drop in the concentration of white blood cells follows, up to their complete absence, which is associated with the development of acquired immunodeficiency syndrome, increased susceptibility of the patient's body to various infections, including opportunistic ones. Lymphocytopenia may begin to regress only after long-term antiretroviral therapy.
In addition, the following viral infections contribute to the destruction of lymphocytes, in which lymphocytopenia is much less pronounced than in HIV:
The cause of lymphocytopenia can also be some bacterial infections - leptospirosis, ehrlichiosis, legionellosis. The greatest significance is lymphopenia in such a common infection as tuberculosis (miliary, disseminated). In this disease, there is a decrease in T-helpers, T-suppressors (CD4, CD8 cells). Pathology occurs in septic conditions (bacterial infection of the blood). Absolute lymphocytopenia indicates an unfavorable course of any bacterial infection. Indicators quickly return to normal after antibacterial and anti-tuberculosis therapy.
Another cause of lymphocytopenia is chronic inflammatory diseases of an autoimmune nature. Numerous studies have revealed two main pathogenetic mechanisms of lymphopenia in these pathologies - the release of anti-lymphocyte antibodies and a decrease in the expression of special proteins (CD55, CD59) on the membranes of immune cells that protect cells from complement-mediated cytolysis. Lymphocytopenia is usually moderate, may correlate with the severity of the disease, regresses during remission or under the influence of pathogenetic treatment.
Oncohematological pathologies, such as lymphogranulomatosis (Hodgkin's lymphoma), T-B-cell lymphomas, lymphosarcomas, can also cause lymphocytopenia. It usually develops in the late stages of the disease and is considered one of the criteria for an unfavorable outcome. The fall in the level of lymphocytes is due to the depletion of lymphoid tissue and the replacement of hematopoietic tissue with atypical malignant cells.
The level of lymphocytes is measured by counting the leukocyte formula in a clinical blood test. Since the range of diseases that can cause lymphopenia is quite wide, if it is detected, you should consult a doctor for a detailed examination. Based on clinical, anamnestic data, the specialist draws up a program of diagnostic studies, which includes:
Complete blood count - a method for detecting lymphopenia
There is no way to treat lymphocytopenia on its own. To normalize the level of lymphocytes, it is necessary to eliminate the cause, namely, to treat the underlying pathology. If lymphocytopenia occurs due to stress or protein deficiency in the diet, treatment is not required, it is enough to adjust the diet. With persistent long-term lymphopenia, medical intervention is necessary. Depending on the cause, the following measures are applied:
Lymphocytopenia is quite often a predictor of poor prognosis, associated with an increased risk of infectious diseases and activation of opportunistic microflora. The outcome and life expectancy of patients are determined by the underlying pathology, against which lymphopenia arose. The most benign is lymphocytopenia, which developed after prolonged stress or during protein starvation. Hereditary immunodeficiency states and oncohematological diseases are characterized by a high probability of death in the early stages.